Cubs rotation troubles exposed once again as Donn Roach falters

An early knockout of Donn Roach accentuated and accelerated the Cubs' need for more starting pitching depth.

But it might not be so easy to correct until at least after the All-Star break, and only if there is significant separation between playoff contending teams and pretenders.

"There's a chance this is one of the tightest markets we've ever seen, and we have to be creative," general manager Jed Hoyer said Saturday night as he watched a Cubs starter fail to pitch more than five innings for the fourth time in their last six games.

"A lot of times we'll have to be creative because there are not going to be a lot of sellers. And we keep assuming the next four to five weeks we'll see some of that shake out, but we may not."

Meanwhile, the Cardinals' mastery of the Cubs continued in an 8-1 humbling that extended the Cubs' losing streak to four games — equaling a season high — and stretched the Cardinals lead over the Cubs in the National League Central to 10 1/2 games.

The Cubs missed scoring opportunities against Michael Wacha in the third and fourth innings and their failings were magnified when the Cardinals scored eight times in the fourth and fifth off Roach and Travis Wood.

"That's what we have to get good at," manager Joe Maddon said after the Cubs were 1-for-8 with runners in scoring position, 4-for-27 in those situations during their four-game skid.

Roach, 25, emerged from a thin cast of candidates at Triple-A Iowa to take the place of injured left-hander Tsuyoshi Wada. The Cubs' starting pitching depth has been thinned by the struggles and injuries of Dallas Beeler, Eric Jokisch and Pierce Johnson, as well as an elbow injury to Jacob Turner in spring training.

"It has been a struggle and hopefully our guys will stay healthy, but we have to address it here at the trade deadline," Hoyer said.

Aiming for a high-salaried pitcher could affect the Cubs offseason spending as they are expected to pursue potential free agents Jordan Zimmermann of the Nationals and David Price of the Tigers.

There's also the balancing act of deciding which prospects to trade who won't haunt you later. Hoyer mentioned the Braves and Giants executive Brian Sabean for possessing a knack for dealing the right players in return for championship-caliber veterans.

"Trading your prospects can help in the near term, but there's a price to be paid for that, and that price is not having that depth," Hoyer said. "It's something we have to consider when making those moves."

There's also the risk of waiting too long to move a prospect and watching his value drop. Some scouts believe that is the case with switch-hitting infielder-outfielder Arismendy Alcantara, who is batting .256 at Iowa after being optioned from the Cubs two weeks into the season.

Nevertheless, Hoyer knows what's at stake with the Cubs (39-34) possessing a reasonable chance to compete for a wild-card playoff berth. And Maddon, looking from a scout's view, knows how important pitching depth is to the Cardinals' success.